A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve.

Developmental hypoplasia of the dental enamel.

Secondary retention is the cessation of eruption of a tooth after emergence that does not result from a physical barrier in the path of eruption or an abnormal position of the tooth. Permanent molars are less frequently affected than deciduous molars. The major characteristic of a secondarily retained molar is infraocclusion, which may result in malocclusion because of tilting of the neighboring teeth and overeruption of antagonists. The disorder can also result in loss of the retained molar and neighboring teeth due to caries and periodontal disease and in deformation of the facial skeleton (Raghoebar et al., 1992). See also 125350 and 273050 for phenotypes with shared features of secondary retention of permanent molars.

Delayed tooth eruption, which can be defined as tooth eruption more than 2 SD beyond the mean eruption age.

Increased volume of dental pulp of permanent molar characterized by a crown body-root ratio equal or larger than 1:1 or an elongated pulp chambers and apical displacement of the bifurcation or trifurcation of the roots.

Dentin dysplasia type II (DTDP2) is a defect of dentin formation in which the clinical appearance of the secondary teeth is normal, but the primary teeth may appear opalescent, similar to teeth affected by dentinogenesis imperfecta. The roots of the teeth are of normal shape and morphologic character. The pulp chambers and root canals of the anterior teeth and the premolars are shaped like thistle tubes because of the radicular extension of the pulp chamber. Most teeth show accumulations of pulp stones in these unusually shaped pulp chambers (summary by Kalk et al., 1998). Also see dentin dysplasia type I (DTDP1; 125400).

Facial height (length) is more than 2 standard deviations above the mean (objective); or, an apparent increase in the height (length) of the face (subjective).

Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).

Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border.

Agenesis of premolar tooth.

Coloboma is an eye abnormality that occurs before birth. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in one of several parts of the eye, including the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or the optic nerves, which carry information from the eyes to the brain.\n\nColobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. Colobomas affecting the iris, which result in a "keyhole" appearance of the pupil, generally do not lead to vision loss. Colobomas involving the retina result in vision loss in specific parts of the visual field. Large retinal colobomas or those affecting the optic nerve can cause low vision, which means vision loss that cannot be completely corrected with glasses or contact lenses.\n\nSome people with coloboma also have a condition called microphthalmia. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss.\n\nPeople with coloboma may also have other eye abnormalities, including clouding of the lens of the eye (cataract), increased pressure inside the eye (glaucoma) that can damage the optic nerve, vision problems such as nearsightedness (myopia), involuntary back-and-forth eye movements (nystagmus), or separation of the retina from the back of the eye (retinal detachment).\n\nColobomas involving the eyeball should be distinguished from gaps that occur in the eyelids. While these eyelid gaps are also called colobomas, they arise from abnormalities in different structures during early development.\n\nSome individuals have coloboma as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When coloboma occurs by itself, it is described as nonsyndromic or isolated.